and many more benefits!

Find us on Facebook

GMAT Club Timer Informer

Hi GMATClubber!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: Scientists analyzing air bubbles that had been trapped in [#permalink]
07 Apr 2012, 10:19

Premise: Scientists analyzing air bubbles that had been trapped in Antarctic ice during the Earth’s last ice age found that the ice-age atmosphere had contained unusually large amounts of ferrous material and surprisingly small amounts of carbon dioxide. One scientist noted that algae absorb carbon dioxide from the atmosphere.

Conclusion: ferrous material promoted a great increase in the population of Antarctica algae such as diatoms.

Which one of the following, if true, would most seriously undermine the scientist’s hypothesis?

A) Diatoms are a microscopic form of algae that has remained largely unchanged since the last ice age.Only Diatoms has remained unchanged; other types of Algae may have increased - we do not know

(B) Computer models suggest that a large increase in ferrous material today could greatly promote the growth of oceanic algae. - Strengthens the argument

(C) The dust found in the air bubbles trapped in Antarctica ice contained other minerals in addition to the ferrous material.Something else besides Ferrous material might be the reason

(D) Sediment from the ocean floor near Antarctica reflects no increase, during the last ice age, in the rate at which the shells that diatoms leave when they die accumulated.No increase in death; does that mean the population decreased? NO

(E) Algae that currently grow in the oceans near Antarctica do not appear to be harmed by even a large increase in exposure to ferrous material. No harm because of ferrous material but does it benefits the growth?

Only C is coming close to undermining the argument. _________________

--Syed" Some are desperate for success, and therefore destined for it."

Re: Scientists analyzing air bubbles that had been trapped in [#permalink]
02 Oct 2012, 23:10

Expert's post

Guys are saying that option D is within scope. I doubt!This option describes a scenario near Antarctica. HOW COULD THIS BE CORRECT?C correctly describes that there may be other minerals that might have been the reason behind the increase in population of algae.Verbal experts please explain the correct answer. _________________

Re: Scientists analyzing air bubbles that had been trapped in [#permalink]
03 Oct 2012, 08:39

Scientists analyzing air bubbles that had been trapped in Antarctic ice during the Earth’s last ice age found that the ice-age atmosphere had contained unusually large amounts of ferrous material and surprisingly small amounts of carbon dioxide. One scientist noted that algae absorb carbon dioxide from the atmosphere. The scientist hypothesized that the ferrous material, which was contained in atmospheric dust, had promoted a great increase in the population of Antarctica algae such as diatoms.

Which one of the following, if true, would most seriously undermine the scientist’s hypothesis?

A) Diatoms are a microscopic form of algae that has remained largely unchanged since the last ice age.talks about diatoms(population has remained unchanged) in general, not specifically about Antarctica region.(B) Computer models suggest that a large increase in ferrous material today could greatly promote the growth of oceanic algae.Incorrect - Strengthens the argument(C) The dust found in the air bubbles trapped in Antarctica ice contained other minerals in addition to the ferrous material.The statement mentions that air bubbles contained other minerals but if other minerals caused increase in algae population is assuming too much for me. what if they were harmful...(D) Sediment from the ocean floor near Antarctica reflects no increase, during the last ice age, in the rate at which the shells that diatoms leave when they die accumulated.specifically talks about diatoms population around Antarctica region. Correct. (E) Algae that currently grow in the oceans near Antarctica do not appear to be harmed by even a large increase in exposure to ferrous material.neutral or a weak strengthner because it says ferrous material is not harmful to algae population._________________

Re: Scientists analyzing air bubbles that had been trapped in [#permalink]
26 May 2013, 11:55

vaibhav87 wrote:

Scientists analyzing air bubbles that had been trapped in Antarctic ice during the Earth’s last ice age found that the ice-age atmosphere had contained unusually large amounts of ferrous material and surprisingly small amounts of carbon dioxide. One scientist noted that algae absorb carbon dioxide from the atmosphere. The scientist hypothesized that the ferrous material, which was contained in atmospheric dust, had promoted a great increase in the population of Antarctica algae such as diatoms.

Which one of the following, if true, would most seriously undermine the scientist’s hypothesis?

A) Diatoms are a microscopic form of algae that has remained largely unchanged since the last ice age.

(B) Computer models suggest that a large increase in ferrous material today could greatly promote the growth of oceanic algae.

(C) The dust found in the air bubbles trapped in Antarctica ice contained other minerals in addition to the ferrous material.

(D) Sediment from the ocean floor near Antarctica reflects no increase, during the last ice age, in the rate at which the shells that diatoms leave when they die accumulated.

(E) Algae that currently grow in the oceans near Antarctica do not appear to be harmed by even a large increase in exposure to ferrous material.

Answer is C , in my opinion. We need to undermine the scientists hypothesis that "ferrous material had promoted increase in algae" ...OPtion C says , "there were couple of other stuffs found in the air bubbles trapped in the ice" , gives us a reason to believe that something else might have promoted an increase in algae - and hence doubt scientists hypothesis that ferrous is responsible for an increase.

Whereas, Option D , undermines the premise , but not the scientists hypothesis/conclusion. The premise says that there was an increase in algae then. D only lets us know that there might not be an increase in the algae back then . But we are not supposed to undermine the premise and rather are supposed to take it to be true. In this view, D does nothing to undermine the conclusion that "ferrous led to the increase in algae".

Re: Scientists analyzing air bubbles that had been trapped in [#permalink]
10 Jun 2013, 20:14

Answer D according to me.

Scientists analyzing air bubbles that had been trapped in Antarctic ice during the Earth’s last ice age found that the ice-age atmosphere had contained unusually large amounts of ferrous material and surprisingly small amounts of carbon dioxide. One scientist noted that algae absorb carbon dioxide from the atmosphere. The scientist hypothesized that the ferrous material, which was contained in atmospheric dust, had promoted a great increase in the population of Antarctica algae such as diatoms.

Summary: Scientists found that the atmosphere during the last ice age had large amounts of ferrous material and very less carbon dioxide. Explanation for very less carbon dioxide was that algae absorbed it.Hypothesis: The increase in algae was because of the ferrous material.

Which one of the following, if true, would most seriously undermine the scientist’s hypothesis?

Thought process: How can we weaken the Hypothesis?Either we say the cause of the increase was not ferrous material, or we say there was no increase in algae whatsoever!"No-increase-whatsoever" gives a lethal blow to the hypothesis!

A) Diatoms are a microscopic form of algae that has remained largely unchanged since the last ice age.Talks about Diatoms, but not about "no increase whatsoever"

(B) Computer models suggest that a large increase in ferrous material today could greatly promote the growth of oceanic algae.Says there was "definitely an increase!", thereby strengthening the argument.

(C) The dust found in the air bubbles trapped in Antarctica ice contained other minerals in addition to the ferrous material.Talks about "other minerals". This does not imply "other minerals caused the increase in algae." Close, but definitely not convincing enough to destroy the hypothesis

(D) Sediment from the ocean floor near Antarctica reflects no increase, during the last ice age, in the rate at which the shells that diatoms leave when they die accumulated.No increase in the mortal remains of algae! No increase in algae whatsoever! This is surely the answer

(E) Algae that currently grow in the oceans near Antarctica do not appear to be harmed by even a large increase in exposure to ferrous material.Talks about algae of today and not about algae during the last Ice Age.

So answer according to me is D. _________________

Always aim at the moon. Never mind if you miss, you will fall in the stars

Re: Scientists analyzing air bubbles that had been trapped in [#permalink]
11 Jun 2013, 06:46

vaibhav87 wrote:

Scientists analyzing air bubbles that had been trapped in Antarctic ice during the Earth’s last ice age found that the ice-age atmosphere had contained unusually large amounts of ferrous material and surprisingly small amounts of carbon dioxide. One scientist noted that algae absorb carbon dioxide from the atmosphere. The scientist hypothesized that the ferrous material, which was contained in atmospheric dust, had promoted a great increase in the population of Antarctica algae such as diatoms.

Which one of the following, if true, would most seriously undermine the scientist’s hypothesis?

A) Diatoms are a microscopic form of algae that has remained largely unchanged since the last ice age.

(B) Computer models suggest that a large increase in ferrous material today could greatly promote the growth of oceanic algae.

(C) The dust found in the air bubbles trapped in Antarctica ice contained other minerals in addition to the ferrous material.

(D) Sediment from the ocean floor near Antarctica reflects no increase, during the last ice age, in the rate at which the shells that diatoms leave when they die accumulated.

(E) Algae that currently grow in the oceans near Antarctica do not appear to be harmed by even a large increase in exposure to ferrous material.

In causality questions when argument say X cause Y I try to look 3 things 1) Maybe Y cause X2)Something else cause Y3) Y and X happens in the same time by coincidence

The argument states that The scientist hypothesized that the ferrous material, which was contained in atmospheric dust, had promoted a great increase in the population of Antarctica algae such as diatoms.And in this example in C is looks like good example of Maybe not Ferrous material but something else may cause increase in algeas

Re: Scientists analyzing air bubbles that had been trapped in [#permalink]
12 Jun 2013, 23:32

Answer should be A, because here if we look at choice D, which says "sediment from the ocean floor near Antarctica reflects no increase, during the last ice age, in the rate at which the shells that diatoms leave when they die accumulated."this choice shows no meaning to me, as weakening is concerned. as there is no increase in sediments, which points to shell that diatoms leave when they die.

As for A choice is concerned" Diatoms are a microscopic form of algae that has remained largely unchanged since the last ice age." Diatoms are unchanged, that is giving some counter to conclusion "great increase in the population of Antarctica algae such as diatoms.".

gmatclubot

Re: Scientists analyzing air bubbles that had been trapped in
[#permalink]
12 Jun 2013, 23:32